#region The MIT License
// The MIT License
// 
// Copyright (c) 2009 octalforty studios
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#endregion
using System;
using System.ComponentModel.Composition;
using System.Diagnostics;
using System.IO;

using octalforty.Componento.ComponentModel.Installation.Web;

namespace octalforty.Componento.ComponentModel.Installation
{
    [ResourceProvider()]
    public class HttpFileResourceProvider : IResourceProvider
    {
        #region Private Fields
        private IWebRequestFactoryService webRequestFactory;
        #endregion

        #region Public Properties
        /// <summary>
        /// Gets or sets a reference to the <see cref="IWebRequestFactoryService"/>.
        /// </summary>
        [Import()]
        public IWebRequestFactoryService WebRequestFactory
        {
            [DebuggerStepThrough]
            get { return webRequestFactory; }
            [DebuggerStepThrough]
            set { webRequestFactory = value; }
        }
        #endregion

        #region IResourceProvider Members
        /// <summary>
        /// Verifies whether current <see cref="IResourceProvider"/> can retrieve resources from <paramref name="uri"/>.
        /// </summary>
        /// <param name="uri"></param>
        /// <returns></returns>
        public bool CanProvideResourcesFrom(Uri uri)
        {
            return uri.Scheme.ToLowerInvariant() == "http";
        }

        /// <summary>
        /// Retrieves resources from <paramref name="uri"/> for package <paramref name="packageName"/> with
        /// version requirement <paramref name="versionRequirement"/>.
        /// </summary>
        /// <param name="uri"></param>
        /// <param name="packageName"></param>
        /// <param name="versionRequirement"></param>
        /// <returns></returns>
        public Uri[] GetResources(Uri uri, string packageName, VersionRequirement versionRequirement)
        {
            IWebRequest webRequest = WebRequestFactory.CreateWebRequest(WebRequestMethod.Get, uri);

            using(IWebResponse webResponse = webRequest.GetResponse())
            {
                if(webResponse.ContentLength == 0)
                    return null;

                Console.WriteLine("Downloading {0:N1} Kb", webResponse.ContentLength / 1024.0);

                using(Stream responseStream = webResponse.GetResponseStream())
                {
                    string cache = Path.Combine(Directory.GetCurrentDirectory(), 
                                                string.Format(@"_componento\packages\{0}\{1}", uri.GetHashCode(), packageName));
                    if(!Directory.Exists(cache))
                        Directory.CreateDirectory(cache);

                    int bytesRead = 0;
                    byte[] buffer = new byte[2048];

                    string p = Path.Combine(cache, uri.Segments[uri.Segments.Length - 1]);
                    using(FileStream fs = new FileStream(p, FileMode.Create))
                        while((bytesRead = responseStream.Read(buffer, 0, 2048)) != 0)
                        {
                            fs.Write(buffer, 0, bytesRead);
                        } // while

                    return new Uri[] { new Uri(p) };
                } // using
            } // using
        }
        #endregion
    }
}